


Heart's Blood

by newmrsdewinter



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: AKA the rhealeth vampire AU that only one (1) person has asked for, Alternate Universe - Vampire, Angst and Hurt/Comfort, F/F, Forbidden Love, Slight Horror Elements, Vampire!Rhea
Language: English
Status: In-Progress
Published: 2020-07-31
Updated: 2020-08-21
Packaged: 2021-03-06 01:48:37
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 6,996
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25635334
Author URL: https://archiveofourown.org/users/newmrsdewinter/pseuds/newmrsdewinter
Summary: At the behest of the emperor, a lone hunter is sent to Garreg Mach Monastery to steal the heart of the dread horror lurking within. But what lies inside the monastery's crumbling walls isn't an indescribable evil that must be vanquished - only a reclusive vampire whose soulless eyes are haunted by a tale left untold for over a thousand years.
Relationships: My Unit | Byleth/Rhea
Comments: 21
Kudos: 64
Collections: Enabler's Gift Exchange





	1. Chapter 1

**Author's Note:**

  * For [blarfshnorgull](https://archiveofourown.org/users/blarfshnorgull/gifts).



> Lower your pitchforks, babes. They're not related in this one 😘✌️
> 
> To Haley, our beloved loremaster! The day you discovered vampire Rhea, you were so elated that I knew I had to go off the wishlist for your gift. Well - not completely off the list since I did sort of combine both of your Rhea prompts into one fic, but I don’t think this is what you were expecting LOL. I hope you enjoy it! 
> 
> Prompts: I went rogue. This is VERY loosely "Rhea and Sothis family bonding. Make me suffer," and "Rhea post-AZ. Show me those deep feelings of loneliness and regret whlie she returns to Zanado."

Five statues of the saints stand sentry above the crumbling battlements of Garreg Mach Monastery. Side by side, with the solemnity of their once-living counterparts, the intensity of their blind eyes pierce through Byleth’s back as she struggles to lead her mare across the bridge.

“Come on,” Byleth mutters, grunting as she dismounts. She tugs the reins forward, but Trout nickers in a low whine, nervously clopping away from the imposing monastery looming ahead. “What’s the problem now?”

Trout snorts, louder this time, startling a group of ravens from their nests atop the statues. She drops the reins, turning around to face the monastery for the first time. Dusk has settled over the wilderness that has reclaimed the grounds, where nettles and roots thicker than her arm cling to the walls like the ivy. 

Byleth continues to frown at the ruins, observing how long it takes for the ravens to turn into black specks in the mist, soaring above high above the tallest spires. She shudders. Hubert was adamant that no one in living memory had dared to set foot within Garreg Mach’s walls. The monster inside had ravaged those who tried — bones and all. Though Hubert’s judgement was dubious, his intel was usually sound. Byleth had no reason to question him, and asking questions was certain to draw not only his ire, but that of her employer’s as well. 

After all, no one has ever defied Emperor Edelgard and lived to tell the tale. The challenge is almost enough to pique Byleth’s interest, but a job is a job. If the emperor desired this monster’s heart in a box for her birthday, then so be it — that’s what she’ll receive. Byleth will be damned before she allows her skittery mare to ruin the good reputation that Jeralt had built for their mercenary company. 

“Alright, then,” Byleth says, biting back a sigh, noting that they wouldn’t have made it across the rotting drawbridge together anyway. She ties the reins to a post, hoping the wolves would grant Trout reprieve for the night. 

She unbuckles the heavy saddlebag hanging from Trout’s flank. This is the first time she has ever felt woefully unprepared for a kill; Hubert had been vague with the details. He proclaimed that if Byleth was half the mercenary her father once was, then this ought to be a simple task. She would be back in Enbarr with the monster’s heart within a fortnight or sooner, just in time for the celebration. 

The problem is, Hubert never told her what kind of monster haunted the ruins of Garreg Mach Monastery. That was part of the challenge. He refused to specify a weakness, a description, or even a reason why the heart was so valuable. That the emperor desired the monster dead seemed to confer enough value to this task that Byleth should feel honored to complete it, but she can’t help but wonder why he felt the need to be so vague. 

With these doubts in mind, she roots through the saddlebag, reaching for her usual healing vials, hunting knives, and eagle medallion. But her hand hovers over the gaudy silver chest nestled at the very bottom; personally bequeathed by the emperor herself, it was meant to hold the monster’s heart.

Byleth leaves the chest, stuffing a rag over it to hide the rubies encrusted on the lid. Kill the beast, cut its heart, and go. It’s a simple plan, though not so simple in execution. First comes surviving the night long enough to search for the monster’s lair; killing it was another matter entirely. Once ready, she lights a torch, leaves Trout at the post and makes her way across the bridge alone. 

The moon competes for space with storm clouds in the sky, shedding slivers of light on the central courtyard before disappearing behind the mist once again. Her footsteps echo in the night. She scans the area, then pauses before the gap-toothed portcullis to gaze up at the statues guarding the entrance. 

Saint Cichol’s piercing eyes glower down upon her with an intensity that makes her skin crawl. His lance towers over his head, poised to strike her with the Goddess’s wrath for daring to desecrate the monastery. Without thinking, her hand goes to the sword at her side to meet his challenge, but she doesn’t unsheathe it. Not yet. 

But before she climbs through the broken gap in the portcullis, she detects an imperceptible shift. Storm clouds drift slowly past the moon, shrouding the statues in darkness, one by one. Out of the very corner of Byleth’s eye, there was no mistaking that the fifth statue, perched at the very end of the battlements, had tilted its head in her direction.

Byleth freezes, but something seizes her ankle, yanking it in the opposite direction. An icy hand grips her heart, but she looks down to see that she had only snagged her boot on a vine that curled across the flagstone.

_It was just a trick of the moonlight. The anticipation is muddling my head, and I was just imagining things._

But she forces herself to turn around slowly, her neck craning so far back that it pops from the effort. When she looks again, the statue is no longer there. 

Her blood freezes in its veins. The monster was here, and she hadn’t even made it past the drawbridge. It knew she was coming. Her own breath, now coming out in haggard gasps, sounds like tearing cloth. Her free hand goes to her sword, but she hesitates before unsheathing it. 

Torch or sword. Byleth can’t wield one without surrendering the other. She stands immobilized in the pool of flickering light, tortured by indecision. Like the other statues lining the battlements, the creature must have been over six feet tall. Fighting it one-handed would be a useless endeavour. 

Against her better judgement, she doesn't unsheathe her sword. She finally climbs through the portcullis and enters the colonnade, eyes squinting through the darkness looming ahead. Even with the light, she can’t see anything that’s a handspans away from her face. She strains to listen to her surroundings, ignoring the thump of her pulse roaring through her ears. 

A faint skittering noise echoes from above. Raising the torch, she glances up and shrieks. 

Without warning, the monster, perched directly above her, plummets from the top of the archway. A horror of claws and fangs lunges at her face. 

Byleth pivots out of reach. She drops the torch and darkness rushes in around her. Her sword is unsheathed in a flash, and a blob of blackness scurries out of reach when she swings it in its direction.

But she’s not fast enough to escape its flailing claw. It slices into her leather jerkin as easily as butter, only barely grazing her flesh. She dances out of reach, carefully tracing a semi-circle to keep whatever it was in her line of sight. Then she realizes the futility: it can see in the dark. 

Frustration builds within her because she cannot neither see nor predict its movements. When a cold puff of breath brushes her neck, she parries her blade in the opposite direction, astonished when the tip almost collides with something solid, drawing a sharp gasp from her assailant.

For a fleeting second, Byleth thinks her sword has grazed its torso — but it flies out of reach, too godly fast to tell whether she had truly wounded it. 

“A valiant effort,” murmurs a low voice now very close to her ear. “But not good enough.” 

Byleth whirls around, but it streaks out of sight. A forceful gust of wind blows past the central courtyard, and the clouds drift across the moon. It glows brighter than ever before, throwing the shadows cast by the colonnade into sharp relief. It’s only through this veil of moonlight that she spies it advancing towards her from the other end of the corridor. 

Her heart pounds so strongly in her chest that she can feel her skin vibrate. _Vampire,_ she realizes to her horror, and she backs away until her feet hit the balustrade. Now it comes as no surprise that Hubert intentionally omitted the details for this assignment. 

A pair of wings curls out from the vampire’s spine, dragging along the stonework with a hideous scraping noise. Gossamer green hair frames a face whose lips are pulled back in a snarl that reveals both of her fangs. She advances forward slowly, purposefully, but comes to a dead halt in the middle of the corridor, holding herself unnaturally still. 

They size each other up. The stillness allows Byleth to drink in every lovely feature of the vampire’s face: her seaglass green eyes, her proud chin, and the porcelain complexion that seems to absorb the moonlight, casting an ethereal glow over her otherwise gaunt features. 

“You’re too slow, mortal,” the vampire taunts with bared fangs, licking her lips. “I can see your knuckles clenching before you swing. You lasted longer than the others, I’ll admit, but no doubt you’ll taste just as sweet.” 

Byleth opens her mouth to shriek again, but instead comes to a startling realization. _I can talk my way out of this,_ she thinks to her own astonishment. _I can do it._ She grips her sword with sweaty hands and readies herself into a defensive position, but the vampire is already upon her in an abrupt burst of movement. 

A clammy, rigid hand seizes her by the collar and dashes her against a column with enough force to crack her ribs. Her sword flies out of her hands. The impact centers around her leg, and her ankle explodes into pain.

“You tread sacred ground,” the vampire hisses. Her eyes are alight with a fury that burns in their sockets, burning brighter than the flames in Aillel. “Last words before I suck you dry. Make them quick!” 

All the air is squeezed out of Byleth’s lungs. She fights the the vice-like grip on her windpipe, sputtering, “Y-Y-You’re —” 

Black claws curl into her neck tightly, breaking skin. “Speak quickly!” 

“You’re beautiful,” Byleth rasps breathlessly, mesmerized by her eyes. 

The vampire is shocked into silence. The anger freezes upon her face. Tilting her head, she loosens her grip on Byleth’s neck just enough to allow a rush of air into her lungs. “Choose your next words _very_ wisely, mortal.” 

It’s not enough air. Byleth kicks helplessly against the column. A wave of dizzying numbness courses through her entire body. “Wh-What —” 

“My patience grows exceedingly thin. _What do you want_?” 

Byleth blurts the first thing that comes to mind: “Your name!” she gasps with one final, haggard breath before falling unconscious. 

With a startled yelp, the vampire braces Byleth’s now-limp body against the column. She is shouting, but Byleth cannot hear her. Darkness overtakes her senses, and the last thing she sees is the vampire’s eyes, shimmering with unshed tears.

It happens too quickly to question whether the sorrow had been real. 

* * *

In Byleth’s dreams, there is a ruined cathedral, and at the far end of that mausoleum, there is an altar upon which sits the emperor's silver chest. The chest is not still. It vibrates most violently, animated by an unseen force that causes it to rattle like a cage.

Byleth crosses the center aisle at a slow funeral march, bewitched by a morbid fascination that tugs her towards the altar. Her very last encounter with Hubert in Enbarr replays in her mind with striking clarity. Contempt drips from his every word — contempt, fear, and perhaps even awe. 

_What kind of monster awaits me at Garreg Mach?_ Byleth remembers asking him. _What are its weak points? What does it look like?_

The altar is within sight. Hubert’s reply reverberates in her mind with every step she takes up the dais, ringing in overlapping echoes that thump in tune with her heart. 

_This monster is a hellsent scourge upon this earth. Its cold, foul claws have a hunger that can never be sated, and it yearns and yearns and yearns without knowing what’s enough._

_But what does it hunger for?_ Byleth had insisted. _What does it feed upon?_

_Go to Garreg Mach and you will see. If you saw those fangs sharpened on the bones of a thousand corpses you would know. Dismiss my warnings as farce, and you’ll pay the price that all the others before you have paid._

The silver chest rattles, disturbed by the force of what is trapped inside. Byleth stands before it, hesitating before lifting the lid. She fully expects the unknown to fly at her face, but that’s not what happens. 

With a slight creak, the lid opens of its own accord. Nestled at the very center is a live heart that pulses with such ferocity that the blood expelled by its valves leak from its chambers and overflow onto the floor.

Possessed by some strange, ghastly madness, Byleth reaches out a bare hand to pick up the organ — perhaps to present it to the emperor, or to squeeze the life out of it, she doesn’t know — only recoil in horror when she registers the large, gaping hole in her chest and her palms dripping with her own lifeblood. 

This terror alone is enough to tear her attention away from her crimson palms to the long claws where her nails should be, and her eyes dart to the tendrils of green hair curling down her gown. She seizes the chest from the altar, and the heart tumbles to the ground, still beating. 

And it’s not until she forces herself to look at her reflection, mirrored in the crimson light of the rubies, that she sees that the face she wears is not her own, but the vampire’s — revolted, anguished, and confused.

* * *

Byleth gasps awake, choking back a shuddering sob. The scent of rotting wood is the first to hit her senses — then comes the dull, throbbing pain at the center of her chest, and she sneezes back to consciousness, lifting from her bed as though pulled by an invisible string. The chandelier overhead rains dust motes so thick from its prisms that they immediately tickle the back of her throat. 

_I’ve never dreamed a nightmare so vivid before. What could it mean? What might it portend?_

Byleth sinks back into the mattress, unable to move her right leg. Her entire body aches in protest at the slightest movement. She forces her eyes shut. Nightmare and memory have blended into one horrid, ugly blur — one where she cannot sift through her recollections for a source of comfort to anchor her to reality. All she sees in her mind’s eye is the chest, that cursed chest she wants nothing more than to dash against the wall into pieces.

Lying still abed, it takes her a moment to adjust to the darkness, and several moments more before she makes sense of the room around her. Much of the walls and furniture had crumbled into disarray, ravaged by time. The bedding is saggy and moth-eaten, but Byleth detects no soreness in her muscles from lying abed for several hours — or days. She doesn’t know how long it’s been since the harrowing encounter with the vampire. 

She presses a hand over her breast and inhales deeply. Her own thundering heart might leap out of her chest, but at least it’s still beating, proof that she is alive and breathing, not a bloodless sack of flesh. 

Her hand flies to her neck, feeling for puncture marks. There are none, thankfully, though the shock has pulled her out of her grogginess enough to realize she wouldn’t be alive if she had been bitten. 

_Do you understand now?_ Hubert’s smug reprimand comes to her in a low croon. _Do you understand why it must be killed?_

Byleth forces his nagging, insistent voice out of her head, pushes away all the unanswered questions that bubble to the surface of her mind. No, she still doesn’t understand, and though the hostility she encountered should have provided the answers she needed. All she can recall from the ambush is the vampire’s sorrowful eyes, and that is the most confounding element of all.

A shadow falls over the open doorway. It doesn’t register to Byleth that she might still be in danger until she spies the vampire quietly entering the room in a pool of moonlight. 

They both freeze when they see each other. Byleth’s attention is immediately taken by the vampire’s tattered white gown, the tea tray she carries, and finally to her bare shoulders, so pale and smooth like marble that her eyes appear even more brilliantly green in the darkness.

“You’re finally awake,” the vampire says, pointedly ignoring Byleth’s gawping. She crosses the room to place the tray on the sideboard, and once her back is turned, Byleth hastily wipes the drool stains from her chin. “I do wish I could tell you how many days have lapsed, but I have little need to keep a record of time.” 

Byleth scarcely draws a single breath through this one-sided exchange. Dumbfounded, she watches the vampire methodically crush some herbs into a pot of healing salve and pour a cup of tea. Once finished, she places the steaming cup within Byleth’s reach, causing the latter’s heart to plummet into her stomach. 

The emperor’s silver chest sits proudly on the nightstand beside her bed. The rubies on the lid gleam in the moonlight like an omen, and Byleth half-expects it to start rattling as violently as it had in her nightmare. Whether the vampire found it and placed it there as a warning or a reminder, Byleth doesn’t know — her stone, alabaster face puts Byleth’s reputation for detachment to shame. 

“You didn’t kill me,” Byleth whispers dumbly. “Why did you —” 

“Why did I spare you?” the vampire asks, perching herself at Byleth’s bedside. Her voice is soothing, almost melodic in tone without the anger and rage Byleth remembers all too well from their previous encounter. “Why have I taken the trouble to nurse my hunter back to health? The answer is a simple one. Would you like to hear it?” 

Byleth gives the slightest nod, not daring to say a single word. 

“You asked for my name,” the vampire says, to Byleth’s visible astonishment. “You would be the first to pay me such a courtesy in three hundred years. No one has asked, not even once. How odd that such a simple request could have saved the souls of countless others if only they had thought to ask!”

The vampire laughs, but it’s mirthless and resentful. Byleth is awash with an abrupt wave of pity. Not once had she anticipated that talking her way out of certain death might have entailed moving the vampire to bitter tears. Was asking the bare minimum all it took for the vampire to change her mind? 

“My name is Byleth,” Byleth says quickly, seizing the opportunity to introduce herself. She doesn’t think she’ll have the opportunity again. “You — you still haven’t told me yours.” 

The vampire tilts her head as though amused by Byleth’s insistence. “Why does it matter?” she wonders aloud. “Names have never meant anything to mankind. I wager you weren’t even warned what I was before your master sent you here. Is it not enough to know me as the abomination you had been tasked with slaying?” 

Byleth’s face burns. Although she feels strangely compelled to defend her own honor — and even Hubert’s, for that matter — she denies nothing. Not once in her life has she ever felt so confronted by one of her quarries. After all, a job is just a job: gold that puts a meal on a table and a roof over her head. Good mercenaries don’t try humanizing their marks, even if they’re as inhuman as vampires.

“You were crying after I asked,” Byleth replies softly. “That’s all.” 

The vampire’s face twists into an ugly grimace, but it’s a pale echo of the rage from before. “Rhea,” she replies, all cold hauteur before she stands to leave. “My name is Rhea. And much good may it do you to know it!” 

Byleth watches Rhea angrily sweep out of the room, but reads the truth in her eyes before she departs, and knows that she is lying. 

* * *

After that awkward introduction, Byleth fully expects Rhea to chop her into mincemeat for the wolves, but to her absolute shock, the vampire returns night after night to care for her until she recovers. It’s not difficult to adjust her sleeping schedule to Rhea’s odd hours, waking at dusk and falling asleep at dawn’s first light. 

Byleth has trouble reconciling Hubert’s damning condemnation of Rhea’s existence with the docile vampire who delivers her bread and broth every evening. At worst, Rhea can be haughty or distant, but Byleth comes to enjoy their late night conversations. They last until the small hours of morning when Byleth finally nods off to sleep, lulled by Rhea’s voice. She craves news from the outside world, and Byleth is happy to oblige. 

But Rhea never asks about the chest. Not even once. For all the trouble it must have taken her to fish it out of the saddlebag, carry it up to Byleth’s tower, and place it in the most conspicuous area in the room, Rhea’s silent refusal to acknowledge the chest is a louder statement than any pointed question she could have chosen to ask.

Nevertheless, Byleth falls into the habit of perking awake whenever she hears Rhea traipsing up the staircase to her tower. She knows she’s been convalescing in a tower because the only thing she sees from the wide window is the heavens peeking through the curtains, shimmering splendidly with stars. Not even the tree tops are visible from her vantage point, nor even the sloping, rolling hillsides surrounding the monastery. 

_“_ Isn’t it troublesome climbing that winding staircase from far below?"Byleth asks Rhea one stormy night. 

A torrent of rain batters against the rooftop, and Rhea’s hair drips with water as she pokes the fire she had built to keep Byleth warm. Once the flames have been sufficiently stoked, Rhea rises from the fireplace to close the window, shutting out the draft. 

“This is the only inhabitable room in the monastery,” Rhea replies airily, settling herself upon a chaise she had pulled at Byleth’s side. “Most others are in worse states of decay, host to all manner of rodents, weeds, and detritus. This room alone has evaded the damage wrought by the elements.” 

“Perhaps because it’s so high in the sky,” Byleth muses, although it seems an improbable explanation. 

“You may be right,” Rhea says shortly.

Her curt tone signals the end of the conversation. With the clouds blocking the night sky, a familiar melancholy has put a damper on Rhea’s mood, one not unlike the sorrow Byleth had seen in her eyes that first fateful night. It would have been easy to attribute Rhea’s reticence to the weather, but Byleth suspects that something else is at play when she catches Rhea staring at the rubies on the emperor’s silver chest. 

Byleth isn’t quite sure what possesses her to ask, “What happened to the person who used to live in this room?” 

Rhea turns away to stoke the fire one last time before departing for the night. 

“She died a horrible death, I’m afraid.” 


	2. Chapter 2

**Notes for the Chapter:**

> Thank you to Acquasole for looking over the first scene for some quick feedback (and also for gifting me some truly devious ideas to write later).

The dreaded question arrives soon after Byleth is well enough to sit up on her own. All of her attempts to keep track of time have ended in futility. One night blends seamlessly into the next during her waking hours, and her head is so foggy from sleep that thinking becomes a labored task. She doesn’t know how long she can maintain this charade with Rhea before her resolve cracks. 

However, Byleth is certain that it’s been at least two weeks since her arrival at Garreg Mach. Two weeks, and she promised Hubert she’d be back in Enbarr in time for the emperor’s birthday. Byleth’s prolonged absence was sure to draw questions, but none pressing enough to send out a search party for her body. Recovering the body of one dead hunter is not worth risking the lives of the emperor’s most prized battalion, especially not when the adversary in question is a deadly vampire. 

It shouldn’t come as a surprise that Rhea was the one who dressed Byleth’s bandages while she was unconscious, but once the time comes to transition from a cast to a splint, she almost jumps out of her skin upon seeing Rhea approach her with a pair of sharp scissors and wooden splint. 

Rhea’s face crumbles into a crestfallen pout. “After all this time, you’re _still_ afraid that I am going to eat you. At this point, I don’t know what else I can say or do to convince you otherwise.” 

“Sorry,” Byleth says quickly, forcing herself to relax. She reaches for her cup of now-cold tea, but glances at Rhea from above the rim before sipping. “But the thought _has_ crossed your mind.” 

Rhea scoffs. “Of course it has. But killing you would put my efforts to save you to waste, would it not?” 

Byleth nods, sipping her tea. 

“The more pertinent question,” Rhea says, baring her fangs in a smile as she perches herself at Byleth’s bedside, “is whether _you_ still intend to kill _me_.” 

Byleth makes a concerted effort to avoid glancing at the emperor’s silver chest, still sitting ominously on the nightstand. Restful sleep has eluded her ever since that first nightmare, and she blames the chest’s presence for her lack of sleep. The rubies gleam like blood drops after a fresh kill, a sight that never once disquieted Byleth before, but now consumes her with strange, unfamiliar guilt.

_What happened to the girl who used to live here? How did she die? Did Rhea know her when she was alive?_

With such limited mobility, there’s not much that Byleth can discern from her surroundings for clues. The room is illuminated by little more than the moon before Rhea lights the fireplace each night; by day, the rotting, velvet curtains are drawn tightly across the windows to block all rays of natural light. Under the watchful eyes of the spiders weaving their canopies atop the moldering furniture, this room stands as nothing more than a relic of its deceased owner, hiding all the mysteries of the past. 

_How does Rhea know that this girl died a horrible death?_

“It’s a valid question, you know,” Rhea says, jolting Byleth out of her reverie. “I don’t often spend time with my would-be killers.” 

Byleth’s stomach lurches as Rhea approaches the bed. “What?” 

Rhea smiles indulgently, patting Byleth’s covered knee. “May I? This will be over in just a moment.” 

Instead of dwelling on it further, Byleth scoots back, allowing Rhea to pull back the covers, exposing her fractured leg to the cool night air. She tries not to shiver when Rhea slices through the soiled bandaging to assess the break. Her touch is gentle, featherlight, but had she plunged her hands into a bucket of icy rainwater, they would not be nearly as frosty as her skin when it’s dry. 

“Humans are such fragile creatures,” Rhea murmurs, tsk’ing quietly at the ugly wound. After cleaning the wounded area with a damp towel, she scoops up a dollop of healing salve and gently massages it into Byleth’s skin. “I am fully aware of my own strength, but it has been a while since the last….” 

Byleth is much too preoccupied by Rhea’s icy fingers to notice that she had trailed off. This level of care is hardly comparable to the brusque, clinical ministrations of the clerics in Enbarr; Rhea’s touch is both warming and cool, dizzying and disquieting at the same time. Her black claws — pared down to fine points — are a deadly reminder that she doesn’t need scissors to slice through flesh. 

Nevertheless, Byleth is almost irked when Rhea abruptly stops to shoot her a pointed look. 

“Well, you’re an odd one, aren’t you?” Rhea asks with a small huff. 

Byleth nearly slumps over in relief when Rhea pivots to reach for the roll of clean linen. “What do you mean?” 

“I searched your belongings,” Rhea says with surprising frankness, ripping the cloth into smaller strips with her fang. “I found none of the usual rubbish those fools assumed would kill me — garlic, crosses, mirrored coats, or even blessed water.” She laughs at that last one, but Byleth doesn’t understand the joke.

“And that’s what makes me odd?” Byleth asks, still not quite sure what point Rhea was trying to make. 

“Wrong,” Rhea says sourly, shaking her head. “No one has ever tried to _flirt_ with me before. “What in the name of the Goddess were you thinking?” 

“I wasn’t,” Byleth replies dumbly. 

Rhea sighs, pained and beleaguered. “Your lack of self-preservation truly astounds me. Worse men — despicable, monstrous men, all of them — have tried to slay me for nobler reasons. All of them wasted their final words to beg for reprieve. You, on the other hand, used yours to flatter me. If you had died, would it have been worth it?”

Byleth schools her expression back into its usual blank mask of neutrality, but she sighs inwardly. There isn’t an answer to Rhea’s question that she can say aloud without wearing out the goodwill she had gathered so far. 

Rhea seems to find Byleth’s silence highly amusing. She smiles to herself as she begins the painstaking process of dressing Byleth’s leg. 

With Rhea’s attention diverted, Byleth takes the opportunity to study the vampire’s beauty, searching for any chinks in her perfect complexion that might anchor to humanity. There are no blemishes, of course, but there’s also no evidence of a monster without a conscience, one who preys and gorges with no sense of restraint. 

“The line between terror and the truly sublime is a fine one, mortal,” Rhea says much too casually, as though reading Byleth’s thoughts. “I urge you not to cross it.” 

“Byleth,” Byleth murmurs. This time, she is determined not to flinch. “My name is Byleth.” 

“Well, Byleth,” Rhea says, sitting back to assess her handiwork. She winds the linen around Byleth’s leg, then unwinds it when it bunches up and twists beneath her calf. “You’ll tell me if it hurts, won’t you?” 

Nodding, Byleth forces herself still as Rhea gently lifts her leg and places it into the splint. The wood is stiff, but not restrictive, holding the fracture firmly in place. Byleth’s anxiety, once a slow and languid pulse, now simmers closer and closer to a boiling point with every cord that Rhea tightens around the splint. Byleth desperately wishes Rhea would finish quickly to put an end to this tense conversation. 

But Rhea takes her time, and her scorn is thinly veiled when she picks up the thread of her last thought. She rips a strip of linen with a touch more force than necessary. “If you’ve wandered through the heroes’ gallery in the Imperial palace, you’ll find it’s the most horrifying moments in history that are immortalized in paintings. Bloodshed, wrath, and death…all terrible things to behold in life, but beautiful in art.” 

Byleth glances at Rhea’s cold, marble expression while she works and sees the same unyielding fury as those dignified saints guarding the monastery. Suddenly, mistaking Rhea for one of the statues hadn’t been quite as foolish as she thought. 

“One can’t exist without the other,” Rhea murmurs. Her voice grows harsher as they stray further and further away from the original topic, and Byleth can’t remember what they were talking about before. “Humans rarely find solace in beauty _because_ it’s terrible. They want to destroy it, conquer what they refuse to understand. But destroying isn’t enough for your kind: they want to erase it and purge its existence from history.” 

Rhea punctuates her words by knotting the final cord that binds Byleth’s leg to the splint, tightening it into place. Byleth’s attention drifts to Rhea’s nimble black claws and the dried patches of blood on her gown.

_Who were you in your past life? Who was the woman you shed to become the vampire that you are now? How many lives were taken to pay that blood price?_

Byleth clears her throat. “That sounds rather like an admission of guilt.” 

“Does it?” Rhea sounds genuinely taken aback. “This entire time, I was talking about you.” 

Byleth’s mouth goes dry. An indignant protest almost escapes her lips before she realizes that she is both immobilized and unarmed. Her eyes dart between the chest and the dagger no longer at her side. Anxiety burns deep within her, and she falters under the weight of Rhea’s piercing, accusatory stare. 

“I am _not_ going to kill you, Rhea,” Byleth says slowly. Her words are deliberately chosen and measured in tone. “I fully admit to trespassing with ignoble reasons, and you had every right to attack me. Even now, you still retain that right. Killing you would be a sorry way of thanking you for your mercy.”

“Mercy,” Rhea echoes, shaking her head. She scoffs, and Byleth might have mistaken the noise for disbelief if she hadn’t caught the hurt shimmering in the vampire’s eyes. Of all things, Byleth didn’t expect Rhea’s composure to break at that particular word. 

“It wasn’t mercy?” Byleth asks, confused. “Then what —” 

A frigid jolt shoots through Byleth’s whole arm. Rhea has leaned forward to brush her fingers lightly over Byleth’s knuckles. She almost recoils, but Rhea’s expression softens, and Byleth feels an unexpected thrill at the intimacy of her touch.

“You don’t need to spare my feelings, Byleth,” Rhea says kindly. “I know why you were sent here.” 

“I wasn’t told you were a vampire,” Byleth admits. “That’s why I wasn’t carrying any crosses or blessed water. Steal the treasure and leave — those were my orders. If I completed this job to —” She swallows Hubert’s name, clearing her throat. “To my employer’s satisfaction, four more commissions would follow.” 

“Four?” Rhea’s voice trembles slightly. “Four exactly?” 

“Yes.” 

A whole host of emotions flickers through Rhea’s expression in a single instant: shock, despair, and perhaps even resignation — but the moment passes too soon before Byleth can make heads or tails of what it might mean. 

Chewing her lower lip, Rhea pulls at the lace of her threadbare gown, then slumps into the chaise at Byleth’s bedside. “You’re rather forthcoming with your information.” 

“I wasn’t paid for my discretion.” 

Rhea raises a skeptical brow. “Then what were you paid for?” 

“Results,” Byleth says with a mirthless smile. But she leans against the headboard, exhaling noisily. The tense conversation has sapped away her remaining strength, and she has scarcely the energy to keep her eyes open. “My employer caught wind of a rumor concerning a beast who laid waste upon the surrounding villages.” 

Gathering all the soiled linen, Rhea says nothing at first, throwing the strips into the dying hearth and tidying the rest of the room. Byleth should feel relieved that Rhea has finally tired of her company, but something dark in her expression bodes nothing but ill tidings. 

“Believe your rumors,” Rhea says airily. “I’m aware of them too. There _is_ something out there that’s plaguing the villagers, and it’s viler and more destructive than the pestilence that swept through the Kingdom. But it’s not me.” 

The knot in Byleth’s chest tightens at the force behind Rhea’s words. “I — I don't understand. Then who —” 

Rhea blows out the candles as she strides out the door. “I’m hiding from it too.” 

* * *

Byleth has no qualms when temptation rears its ugly head while she dreams. 

Her consciousness is adrift under the touch of cold fingers carding through her hair, tilting her skull back and baring her neck to the moonlight. Rhea closes the distance and steals the breath from Byleth’s lips. They part with no resistance at all, demanding and at the mercy her own desire. Byleth’s body flares when she must stop to gasp for air, but she lingers over Rhea’s mouth before surging forward again for another kiss, this one much bolder than the last. 

But Rhea’s lips alone fail to sate the arousal overwhelming Byleth’s senses. Neither can the fingertips tracing the path of her collarbone nor the whisper of Rhea’s breath drawing shivers along Byleth’s spine. This isn’t a stolen moment, it’s a brazen one: the gleaming prisms from the stained glass window behind them expose their union in all its shamelessness. 

_Let them come_ , Byleth thinks triumphantly, turning pliant under the press of her body against Rhea’s. _Let them look_. 

Her eyes flutter open when Rhea’s lips sear a trail along the slim column of her throat, fangs dragging from the hollow to the swell of her breast. Though Byleth’s recollection is dim, she recognizes this place, those red pulsing eyes glowing in the shadows of the chamber. This time, they are in the Imperial palace, somewhere in the deep recesses of lower levels, where the emperor bolts her treasures and secrets behind guarded vaults. 

“The most prized piece in my collection,” Rhea murmurs against Byleth’s skin. She precisely mimics the emperor’s words — down to the exact cadence, reverence, and tone — in some eerie tableau of Byleth’s last memory of Enbarr. “Yours, my most promising champion, but it’s missing the treasure inside.” 

Something rattles behind them. It echoes louder with every second.

All desire ebbs away as the cacophany anchors Byleth’s senses back to reality. She extricates herself from Rhea’s arms, searching for the familiar cracks and fissures in the gleaming green eyes she knows so well. But only Edelgard’s voice echoes through her mind, that unyielding arrogance that once thrilled her, but terrifies her now. 

“Treasure,” Byleth echoes, shaking her head. “No, not the treasure. I already said that I refuse to —” 

“My chest,” says Edelgard’s voice matter-of-factly, raising Rhea’s hand to the mangled, gaping hole where her heart should beat. Frothy blood drains from the gap, spurting onto the floor with every shuddering gasp Rhea takes. “You _promised_.” 

“Stop. Stop that. I never said —” 

“It’s yours!” she cries with wild eyes. “Her heart is yours too, if you’d only seize it when you had the chance. There’s no need to be so difficult, so —” 

Byleth stifles a scream, pressing her hand to her mouth. The rattling has reached a thunderous crescendo, and she has finally found the source.

The hole in Rhea’s chest has widened into a cavity that encompasses her entire torso, exposing her spine and rib cage. Through the gaps, Byleth glimpses that accursed silver chest sitting ominously on the altar, still rattling, still pattering the forceful double-beat of the phantom heart resting inside. 

Frozen, and with limbs unwilling to move an inch, Byleth almost fails to notice dawn’s first light creeping upon them through the stained glass window. When the golden slant stretches across the chamber, Byleth cries out, leaping forward to shield Rhea from the beam, but when she touches Rhea’s cheek, her anguished visage shatters like glass under her hands.

* * *

Byleth awakes with her heartbeat crashing in her ears. 

Her nightgown is soaking wet, and her arms, neck, and torso are tangled in her sheets. Had she not woken up sooner, she might have strangled herself while sleeping. 

Death by tossing and turning. She almost laughs.

“Goddess,” she mutters to herself in a daze, reaching for the glass of water at her nightstand. Her fingers brush her chest, causing her to jolt. “That — yes, that was bad. Really bad.” 

Ever since Garreg Mach, her dreams had been troubling, but they never turned into full-fledged night terrors before. However, this hadn’t started as a harmless dream: Byleth was openly fantasizing about Rhea until her voice morphed into Edelgard’s, and then it became the most unsettling nightmare she has ever had. 

_I haven’t seen a soul in more than a fortnight,_ she thinks, but she knows her rationalizations are meaningless. Heat rises to her cheeks, flushing her face red when her mind wanders to Rhea’s lips and her cold hands dipping lower and lower beneath her shirt. 

_I haven’t talked to a single living person since I left Enbarr. I’m so cold, always so cold, it was only natural…_

Byleth blows out a frustrated breath, angry at the entire world. None of this would have happened if she hadn’t curried the emperor’s favor during that tournament, if Hubert hadn’t been so damn slippery about the details, and if Rhea hadn’t snapped her leg. The promise of gold and glory had dulled her better senses. No one with a brain waltzes into a vampire’s lair and expects to come out unscathed. 

_Well, I did warn you not to mistake this assignment as an indication that I like you_ , says Hubert's smug voice in the back of her mind.

"Oh, shut up!" Byleth cries, flinging her water across the room. The glass shatters against the wall with a resounding smash, but she feels a momentary twinge of guilt at the mess Rhea would have tidy later that evening. 

To any self-respecting hunter, a kill was only a kill, but now, that kill was someone else’s life. Byleth takes one deep, shuddering breath before flexing the calf of her splinted leg. That distinction ceased to matter the moment she asked for Rhea’s name, and that innocent question would prove to be her downfall. 

_These things aren't supposed to happen. Hunters aren't supposed to pity or fall in love with —_

The silver chest still sits on Byleth’s nightstand. Her leg hasn’t fully recovered. Rhea, though amused and nonplussed by Byleth’s prodding, is as frustratingly evasive as Hubert. There is no love to be found in this lonely tower, only sexual tension she could cut with a knife and an ominous mystery she is desperate to solve. 

She touches her kiss-bitten lips, hardly surprised when her fingertips come away red. The phantom sensation of Rhea’s mouth pressed against her own lingers until morning. 

**Notes for the Chapter:**

> edit: added 4 words for the most gratifying and satisfying word count. was originally 6992. truly a gift.


End file.
